The present invention relates generally to an assembly, such as a sensor assembly positioned within a container containing a sample fluid, and methods of securing elongated members within such assembly. Specifically, the present invention is directed to an assembly and method in which a metallic arrangement is configured to provide therethrough one or more elongated members containing a particular fluid, and is adapted to maintain a temperature of the particular fluid to be substantially the same as a temperature of the sample fluid.
Conventional assemblies (e.g., conventional sensor assemblies) may be used to determine a characteristic of a sample fluid within a container (e.g., within a tank). For example, as described in U.S. Pat. No. 6,234,019, the entire disclosure of which is incorporated herein by reference, the conventional assemblies can be used to determine a temperature of the sample fluid, a pressure associated with the sample fluid, a density of the sample fluid, etc. An exemplary conventional assembly may be affixed to a tank, and can include a housing assembly positioned within the tank. The conventional assembly also may include a first sensor positioned within the tank at a first fluid level of the sample fluid, in which the first sensor is adapted to detect a fluid pressure at the first fluid level. Conventional assembly can also include a second sensor positioned within the tank at a second fluid level below the first fluid level, in which the second sensor is adapted to detect a fluid pressure at the second fluid level. Moreover, a transmitter can also be provided which is adapted to communicate with the first sensor and with the second sensor, and a determining device that is coupled to the transmitter. The transmitter can be further adapted to generate signals corresponding to the density of the sample fluid, and the determining device may be adapted to determine the density of the sample fluid based on such signals.
The first sensor of the conventional assemblies may be in communication with the transmitter via a first tube situated within an opening which is formed through a first rod. The first rod can be positioned within the housing arrangement between the first sensor and the transmitter. Moreover, the first tube can contain a first sensor fluid, and when the first sensor senses the fluid pressure at the first fluid level, the first sensor acts on the first sensor fluid. For example, the first sensor can displace the first sensor fluid, and an amount of the displacement of the first sensor fluid depends on the fluid pressure at the first fluid level. The transmitter can subsequently communicate with the first sensor via the first sensor fluid.
Similarly, the second sensor may be in communication with the transmitter via a second tube situated within an opening which is formed through a second rod. The second rod can be positioned within the housing arrangement between the second sensor and the transmitter, or alternatively, may be positioned within the housing arrangement between the second sensor and the first sensor. Moreover, if the second rod is positioned between the second sensor and the first sensor, the second tube can be provided inside the second rod and the first rod. The second tube can contain a second sensor fluid, and when the second sensor senses the fluid pressure at the second fluid level, the second sensor acts on the second sensor fluid. For example, the second sensor can displace the second sensor fluid, and an amount of the displacement of the second sensor fluid depends on the fluid pressure at the second fluid level. The transmitter can subsequently communicate with the second sensor via the second sensor fluid. Moreover, based on the displacement of the first sensor fluid and the second sensor fluid, the transmitter can generate the signals corresponding to the density of the sample fluid, and the determining device can determine the density of the sample fluid based on such signals.
Nevertheless, in the conventional sensor assembly, when the opening is provided through the first rod and/or the second rod, (e.g., by drilling), it may be difficult to form an opening having a diameter which is substantially the same as a diameter of the first tube and/or the second tube, respectively. Specifically, the diameter of the opening may be substantially greater than the diameter of the first tube and/or the second tube. As such, after the first tube and/or the second tube is inserted inside the first rod and/or the second rod, respectively, there may be air gaps, e.g., voids, provided within the first rod and/or the second rod. When the conventional sensor assembly is positioned inside the tank, such air gaps may adversely affect a transfer of energy between the sample fluid and the first sensor fluid and/or the second sensor fluid.
Consequently, a temperature of the sample fluid may be different than a temperature of the first sensor fluid and/or a temperature of the second sensor fluid. Similarly, the temperature of the first sensor fluid may be different than the temperature of the second sensor fluid. When the temperature of the sample fluid is different than the temperature of the first sensor fluid and/or the temperature of the second sensor fluid, the fluid pressure detected at the first fluid level and/or the second fluid level may be inaccurate. Similarly, when the temperature of the first sensor fluid is different than the temperature of the second sensor fluid, the detected fluid pressure may be inaccurate due to thermal expansion. Consequently, due to this inconsistency, the density of the sample fluid determined by the determining device may also be inaccurate.
Therefore, a need has arisen to provide an assembly, such as a sensor assembly, and a method of securing elongated members within such assembly, which overcome the above-described and other shortcomings of the prior art.
One of the advantages of the present invention is that the assembly, and method are adapted to maintain a temperature of the particular fluid substantially the same as a temperature of the sample fluid. For example, the construction of the assembly of the present invention may prevent air gaps from being provided within an elongated member thereof.
This and other advantages can be achieved with an exemplary embodiment of the assembly and method according to the present invention. This assembly, such as a sensor assembly positioned within a container containing a sample fluid, and the method of securing elongated members within the assembly, are provided for at least such purpose. In particular, one or more of the elongated members (e.g., one or more first tubes, such as metallic tubes) which are adapted to contain a particular fluid may be affixed (e.g., soldered or welded) to a temperature-conducting (e.g., metallic) arrangement. For example, the metallic arrangement can be configured to provide the elongated member therethrough, and the elongated member can have an opening adapted to contain the particular fluid.
In one preferred exemplary embodiment of the present invention, the opening can be a groove formed through (by drilling, chiseling, etc.) an outer surface (e.g., a side portion) of the metallic arrangement, and the particular elongated member can be inserted into the groove via the side portion of the metallic arrangement. In this exemplary embodiment, the arrangement can be soldered to the metallic arrangement such that the solder forms a portion of the outer surface of the metallic arrangement. Further, the metallic arrangement can be affixed (e.g., soldered or welded) to a further elongated member (e.g., a second tube) which is configured to provide the metallic arrangement therethrough. Moreover, the metallic arrangement may maintain a temperature of the particular fluid to be substantially the same as a temperature of the sample fluid. For example, the elongated member can be provided through an opening in the metallic arrangement, and can be affixed to the metallic arrangement using solder. After the elongated member is affixed to the metallic arrangement, the metallic arrangement can be provided through an opening in the further elongated member. Moreover, the metallic arrangement can be affixed to the further elongated member using solder.
According to another exemplary embodiment of the present invention, the assembly can be a sensor assembly. The sensor assembly can include a sensor housing arrangement. In this exemplary embodiment, the further elongated member may be positioned inside the housing arrangement. The sensor assembly also can include a first sensor which is coupled to the housing arrangement or positioned inside the housing arrangement, and the first sensor may be adapted to detect a first fluid pressure of the sample fluid at a first fluid level by acting on the particular fluid. Moreover, the elongated member can include a pair of particular elongated members. For example, a first one of the pair of the elongated members can be adapted to contain the particular fluid, and a second one of this pair can be adapted to contain a further fluid. In this embodiment of the present invention, the metallic arrangement may be further adapted to maintain the temperature of the particular fluid to be substantially the same as a temperature of the further fluid, thereby reducing or even eliminating the problems associated with thermal expansion.
In another exemplary embodiment of the present invention, the sensor assembly can also include a second sensor which is coupled to the housing arrangement or positioned inside the housing arrangement, and the second sensor may adapted to detect a second fluid pressure of the sample fluid at a second fluid level by acting on the further fluid. Moreover, the sensor assembly can include a transmitter situated externally from the container, which is coupled to the housing arrangement or positioned inside the housing arrangement. The transmitter may be adapted to communicate with the first sensor via the particular fluid, and with the second sensor via the further fluid. The transmitter also can be adapted to generate signals corresponding to a density of the sample fluid. The sensor assembly can include a determining device coupled to the transmitter, and the determining device may be adapted to determine the density of the sample fluid based on the signals.
In any of the foregoing exemplary embodiment and other embodiments or variations of the present invention, the metallic arrangement can also be adapted to maintain a first temperature of the particular fluid and/or the further fluid provided at a first end of one of the particular elongated members to be substantially the same as a second temperature of the particular fluid and/or the further fluid provided at a second end of the particular elongated member.